The von Schuckmann U.S. Pat. No. 5,603,434 issued Feb. 18, 1997 discloses a pump dispenser having a trigger-type actuator having a rearward arm which vents the container when the trigger is drawn back. More specifically, the arm brushes a projection on a tubular liner which normally engages about the inside of the tubular support for the pump. The projection raises the line away from the wall of the support to partly uncover a vent opening.
The present invention may be regarded as an improvement on the invention shown in von Schuckmann '484 in that it provides for a funnel-shaped vent seal which assures by its structure a reliable breaking of the seal at positions of the trigger and a reliable closing of the seal when the trigger is released.